Dr Mack embraced a worldview inspired by elements of spiritual and philosophical traditions which hold that we are all connected to one another.

The theme of “connection” to other life was explored most boldly in his study of men and women who reported that recurrent “alien encounter” experiences had affected the way they regarded the world, including a heightened sense of spirituality and environmental concern.

Mack’s interest in the transformational aspects of these extraordinary experiences, and his suggestion that the experience may be more transcendent than physical in nature – yet nonetheless real – was largely reported in the media as a simple endorsement of the reality of alien encounters.

Earlier in is career, he explored how this sense of “connection” developed between different cultures, interviewing political leaders and citizens of the then-Soviet Union and Israel/Palestine in the study of ethno-national conflict and the nuclear arms race.

He won the Pulitzer Prize in Biography in 1977 for A Prince of Our Disorder, his biography of T. E. Lawrence, a British officer stationed in the Middle East who became known as “Lawrence of Arabia”.

Dr Mack suggested that a materialist worldview was the root cause of long-simmering conflicts between the West and other cultures, and was responsible for the global ecological crisis. A shift in perspective was required, he suggested, to restore people’s appreciation of connections to one another and to the natural world.

Mack’s final published book, Passport to the Cosmos: Human Transformation and Alien Encounters(1999), was as much a philosophical treatise connecting the themes of spirituality and modern worldviews as it was the culmination of his work with “experiencers” of alien encounters.

Dr Mack’s credentials provided him with some measure of protection from critics: He received his medical degree from the Harvard Medical School (Cum Laude, 1955) after undergraduate study at Oberlin (Phi Beta Kappa, 1951); a graduate of the Boston Psychoanalytic Society and Institute, and Board certified in child and adult psychoanalysis. He founded the department of psychiatry of the Cambridge Hospital, the teaching hospital of Harvard Medical School.

Nonetheless, in 1994, the Dean of Harvard Medical School appointed a committee of peers to review Mack’s clinical care and clinical investigation of the people who had shared their alien encounters with him. After fourteen months of inquiry, amid growing concerns from the academic community (including Harvard Professor of Law Alan Dershowitz) about the validity of an open-ended investigation of a fulltime professor who was not subject to any claim of ethics violation or professional misconduct, Harvard issued astatement stating that the Dean had “reaffirmed Dr. Mack’s academic freedom to study what he wishes and to state his opinions without impediment,” concluding “Dr. Mack remains a member in good standing of the Harvard Faculty of Medicine.”